Spark gap



N. CODA SPARK GAP Filed April 12, 1967 Dec. 8, 1970 mvmon 72w ATTORNEYUnited States Patent 3,546,538 SPARK GAP Nello Coda, Erie, Pa., assignorto Erie Technological Products, Inc, Erie, Pa., a corporation ofPennsylvania Filed Apr. 12, 1967, Ser. No. 630,349 Int. Cl. H02h 9/06US. Cl. 317-61 3 Claims ABSTRACT OF THE DISCLOSURE A spark gap having abody of insulating material in which is molded a continuous lead wirewhich may be slotted intermediate the ends of the body to provide a gapwhich will break down whenever the voltage is excessive.

This invention is intended to provide a spark gap of simple and ruggedconstruction for protecting electronic circuit components. In apreferred form, a continuous lead wire is molded in a cylindrical bodyand the lead wire is slotted at an intermediate point within the body toprovide the desired spark gap. The slotting may be by punching.

In the drawing, FIG. 1 is a plan view of a spark gap as molded, FIG. 2is an end view, FIG. 3 is a plan view of the completed spark gap, FIG. 4is a plan view of a spark gap with a rectangular body, and FIG. 5 is anedge view of the FIG. 4 gap.

Referring first to FIG. 1 which shows the spark gap as molded, 1indicates a generally cylindrical or pin shaped body of plastic or othermoldable insulating material in which is molded a lead wire 2 whichextends along the axis of the body. The lead wire may have enlargements3 or other suitable interlocking means providing a positive anchor forthe wire. Between the ends of the body is an opening or windowtransverse to the axis of the body and to the wire 2. The manufacture ofthe gap is completed by punching out a section of the wire 2 to form aspark gap 5. The length of the cut out section determines the voltage atwhich the gap breaks down. When a voltage surge causes breakdown of thegap, the spark is confined of the gap as a protective device are notmaterially or sigof the opening 4. The sheared metal ends of the leadwire between which the sparking takes place are subjected to negligibleerosion by the spark so the characteristics of the gap as a protectivedevice are not materially or significantly changed by repeated voltagesurges.

The gap may be cut in a wide range of lengths so single size of moldedpart will accommodate a wide range of voltages. The gap is adapted toautomatic assembly by the same equipment used for circuit components.

The length, breadth and thickness of the opening 4 is each greater thanthe corresponding dimensions of the gap 5. The electrodes of the gap arerecessed inward from Patented Dec. 8, 1970 the ends of the opening 4 andare not easily damaged or distorted by rough or accidental handling.

The characteristics of the gap are determined by the opening 4 and itsrelation to the electrodes of the gap and not by the external shape ofthe body 1 or by the relation of the leads 2 to the body. In FIGS. 4 and5,

the molded plastic body 6 is rectangular and has a U- shaped lead 7molded into the body and projecting from one edge 8. An opening 9transverse to the base section 10 of the lead serves the same functionas the opening 4. The length of the gap 11 punched out of the section 10after molding is determined by the desired breakdown voltage of the gap.The operating characteristics are the same as for the gap with thecylindrical body. The lead may have enlargements 12 to assist inanchoring, if desired.

What is claimed as new is:

1. An article of manufacture comprising a body of molded insulatingmaterial having a continuous lead wire with its intermediate sectionmolded into the body and its ends extending outside the body forconnection into the circuit, and a cut severing said intermediatesection of wire and providing a spark gap between the severed ends ofthe wre which breaks down when the voltage across the gap is excessive,said body having an opening of length, breadth and thickness eachgreater than the corresponding dimension of the gap, said openingextending completely through the body transverse to the intermediatesection of said wire with the sides and ends of the opening spaced fromthe spark gap formed by the cut and the severed ends of the wire beingrecessed inward from all sides and both ends of the opening.

2. The article of claim 1 in which the body is of generally cylindricalshape with the wire extending through and along the longitudinal axis ofthe body.

3. The article of claim 1 in which the body is of generally rectangularshape, the lead wire is of U shape, and the intermediate section of thelead wire which is cut to form the gap is the base section of the U.

References Cited UNITED STATES PATENTS 1,340,657 5/1920 Jacobus 313325X1,946,695 2/1934 Ilberg 315325X 2,966,608 12/ 1960 Magnusson et al. 315-3 6X 3,045,143 7/1962 Shickel 3 17-6 1X 3,289,027 11/1966 Jones3l761X 3,322,995 5/1967 Hansen et al. 31736X 3,202,873 8/1965 Feldman315-209 JAMES D. TRAMMELL, Primary Examiner US. Cl. X.R.

